Vol. 12, Issue 9 (2023)

Growing rice (Oryza Sativa) in soil less culture, hydroponics, is challenging due to problems associated with inappropriate nutrient (s) availability limiting plants normal growth and development. The inorganic ingredients of the nutrient solution become available to plants only in the form of ions at a prescribed pH. Rice genotypes grown in standard Yoshida nutrient solution shows increased drying of the older leaf and reduced plant habit. Among the macronutrients, ammonium nitrate has lesser dissociation rate and acidifies the solution thereby inhibiting root elongation and lateral root formation. In this study, the nitrogen sources in Yoshida nutrient solution were modified accordingly, ammonium nitrate (1.14 M) was replaced by potassium nitrate (1.53 M) and potassium sulphate (0.41 M) by ammonium sulphate (0.50 M) on the basis that the NH4⁺ concentration was reduced by half and NO3 - Level increased three times so as to reduce the problem of pH regulation. Further, the potassium level was increased two times considering its significant role in crop growth. Two rice elite rice cultivars, ASD16 and CO52, cultured under the modified Yoshida nutrient solution demonstrated positive outcomes which include, reduced senescence, improved plant habit, increased root and shoot biomass, proliferative lateral roots, increased leaf width, high photosynthetic efficiency (F_v/F_m) and increased numbers of productive tillers. The root architectural parameters were studied using GiA Roots software. The modified Yoshida nutrient solution demonstrates good growth and developmental features in rice under controlled conditions making it an ideal hydroponic nutrient solution for carrying out molecular and genetic studies.